ann1008 — Announcement

Hubble Gives Clues about Saturn’s “Irregular Heartbeat”

4 August 2010

A European-led team has used the NASA/ESA Hubble Space Telescope to make a startling discovery about Saturn, the Solar System’s second largest planet [1]. The astronomers discovered that Saturn’s aurora, an ethereal ultraviolet glow that illuminates its upper atmosphere near the poles, dances in time to the beat of a mysterious radio emission.

For years, scientists thought that the Saturn Kilometric Radiation (SKR), which shines from Saturn’s polar regions, pulsed in time with the rotation of the planet. However, more recent studies have shown that the rate speeds up and slows down with time. Since planets spin at a constant rate, Saturn’s rotation cannot explain an irregular pulsing of the SKR.

The team, led by the University of Leicester’s Jonathan Nichols, has discovered that the planet’s aurora varies in time with the SKR, pointing to a common explanation for both.

Nichols says: “This is an important discovery for two reasons. First, it provides a long-suspected but hitherto missing link between the radio and auroral emissions, and second, it adds a critical tool in diagnosing the cause of Saturn’s irregular heartbeat.”

The paper, “Variation of Saturn’s UV aurora with SKR phase”, will be published on Friday 6 August in the journal Geophysical Research Letters.

A full press release and further details of the discovery are available from the University of Leicester.

Notes

[1] As of the date of this announcement, the paper by Nichols et al. is still “in press” (i.e. not yet published).